Invertebrates Surveys

Overview

The invertebrate survey (inverts) protocol is used to quantify the diversity, abundance, and size distribution of motile reef invertebrates at Pristine Seas UVS sites. Divers swim along fixed transects and record invertebrate observations within defined belt widths, using two complementary methods:

• Standard invertebrate survey — All motile invertebrates within 1 meter of one side of the transect are counted and identified to the lowest possible taxonomic level.
• Large-scale invertebrate survey — Culturally and fishery important species are measured for size within a wider 4-meter belt on the opposite side of the transect.

This dual protocol captures both fine-scale community composition and large-bodied target species for management applications.

Invertebrate data are organized into three interlinked tables:

• uvs.inverts_stations — Metadata and ecological summaries for each invertebrate transect station
• uvs.inverts_counts — Raw counts and size measurements of individual invertebrate taxa
• uvs.inverts_summary_by_taxa — Station-level summaries by species, including density and average size

All records are linked by ps_station_id, and species are standardized using accepted_aphia_id from taxonomy.inverts.

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Tables

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Stations (uvs.inverts_stations)

This table contains metadata and summary statistics for each invertebrate survey station. Each row corresponds to a single 50 m transect at a UVS site and includes spatial context, survey effort, and ecological indicators such as species richness and density of target taxa.

Transect structure

• Standard inverts: 50 m × 1 m belt on one side of the transect
• Large-scale inverts: 50 m × 4 m belt on the opposite side

Table 1: Schema for uvs.inverts_stations: metadata and summary metrics for motile invertebrate survey stations

Field	Type	Required	Description
ps_station_id	STRING	true	Unique station ID (ps_site_id_depth).
ps_site_id	STRING	true	Foreign key to uvs.sites.
exp_id	STRING	true	Expedition ID (ISO3_YEAR).
method	STRING	true	Survey method (uvs).
protocol	STRING	true	Survey protocol (inverts_motile).
divers	STRING	true	Divers who conducted the invertebrate survey.
region	STRING	true	Region name.
subregion	STRING	true	Subregion name.
locality	STRING	false	Optional local feature (e.g., reef, bay).
latitude	FLOAT	true	Latitude of station (decimal degrees).
longitude	FLOAT	true	Longitude of station (decimal degrees).
date	DATE	true	Date of invertebrate survey.
time	TIME	true	Start time of the survey.
depth_m	FLOAT	true	Average station depth (m).
depth_strata	STRING	true	Depth bin: supershallow, shallow, deep.
habitat	STRING	true	Habitat type.
exposure	STRING	true	Exposure type.
transect_length	FLOAT	true	Length of transect surveyed (typically 50 m).
survey_area_m2	FLOAT	true	Total area surveyed (transect_length x belt_width).
total_richness	INTEGER	false	Total number of unique invertebrate taxa observed at the station (on-transect only).
total_count	INTEGER	false	Total number of invertebrates recorded.
count_m2	FLOAT	false	Mean density (individuals/m²).
notes	STRING	false	Optional QA or field notes.

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Observations (uvs.inverts_observations)

This table stores raw observations of invertebrates recorded during the surveys. Each row represents a single species recorded on a given transect, and includes taxonomic identity, count, and where applicable, size estimates for large-bodied species.

• Species are identified using accepted_name and accepted_aphia_id
• All individuals are counted in the 1 m belt
• Selected species are measured in the 4 m belt (e.g., giant clams, pearl oysters, conchs, sea cucumbers)

Table 2: Schema for uvs.inverts_observations: raw counts and measurements of motile invertebrates per transect

Field	Type	Required	Description
obs_id	STRING	true	Unique observation ID (e.g., FJI_2025_inv_JSD_0001).
ps_station_id	STRING	true	Foreign key to uvs.inverts_stations.
diver	STRING	true	Name of the diver who recorded the observation.
station_label	STRING	true	Field-assigned stratum label (e.g., shallow, deep).
depth_m	FLOAT	true	Recorded depth (m) at which the transect was conducted.
in_transect	BOOLEAN	true	TRUE if observation was made within the standard 1-m or 4-m survey band; FALSE if incidental or off-transect.
accepted_name	STRING	true	Scientific name (Genus species) of the observed taxon.
accepted_aphia_id	INTEGER	true	WoRMS AphiaID — foreign key to taxonomy.inverts.
functional_group	STRING	true	Functional or cultural group (e.g., sea cucumber, clam, urchin). Assigned post-survey.
count	INTEGER	true	Number of individuals observed for this species.
length_cm	FLOAT	false	Measured length (cm), if applicable for the taxon.
measurement_type	STRING	false	Type of length measured (e.g., shell width, total length). Use standardized vocabulary.
survey_band_m	FLOAT	true	Width of the transect band (m) — typically 1 for general surveys, 4 for large-scale surveys.
count_m2	FLOAT	false	Density (individuals/m²), standardized by transect area.
notes	STRING	false	Optional comments or QA annotations.

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Density by taxa

This table summarizes invertebrate density and size metrics by species at each station. It is the primary analysis-ready table for evaluating community structure and assessing the presence of key indicator species.

Each row is a unique combination of ps_station_id and species, with fields such as:

• density_m2 — mean individuals per square meter
• avg_size_cm, min_size_cm, max_size_cm — summary of measured size data

Field	Type	Required	Description
ps_station_id	STRING	true	Unique station ID (ps_site_id_depth).
accepted_name	STRING	true	Scientific name (Genus species) of the observed invertebrate.
accepted_aphia_id	INTEGER	true	WoRMS AphiaID — foreign key to taxonomy.inverts.
functional_group	STRING	true	Functional or cultural grouping (e.g., sea cucumber, clam, urchin).
depth_m	FLOAT	true	Average depth (m) of the station.
depth_strata	STRING	true	Depth bin: supershallow, shallow, or deep.
region	STRING	true	Region name.
subregion	STRING	true	Subregion name.
locality	STRING	false	Optional local feature (e.g., reef, bay, cove).
habitat	STRING	true	Habitat type at the station.
exposure	STRING	true	Exposure type (e.g., windward, leeward, lagoon).
total_count	INTEGER	false	Total number of individuals observed at the station.
total_count_m2	FLOAT	false	Mean density (individuals/m²), standardized by band width and transect length.
avg_length_cm	FLOAT	false	Weighted mean length (cm), if applicable.
min_length_cm	FLOAT	false	Minimum length (cm) observed at the station.
max_length_cm	FLOAT	false	Maximum length (cm) observed at the station.